Mac OS X Mountain Lion has 43 secret desktop wallpapers hidden in one of its folders. They are all beautiful, high quality and this is how you find them.
If you don't like Google following your searches or you simply want to check how some search keywords rank on Google without the need to clear your cache and log off from Google account, then this is for you.
You can visually insert a radio button into your form and set its properties. Use radio buttons when you want users to select only one choice from a set of options.
If you are using Facebook social apps for watching videos, reading content and you don't want your friends or everyone to know about your activity, you can turn this off.
Very useful Javascript feature that can prevent a user from losing the data they are entering in an entry field or text editor in case of unintentional leaving of a page.